Fiber board



Patented Dec. 22, 1925.

UNITED STATES PATENT OFFICE.

ALBERT L. OLAPP, OF DANVERS, MASSACHUSETTS, ASSIGNOR TO BEGKWITH MANU- FACTURING COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS.

FIBER BOARD.

No Drawing.

To all whom it may concern:

Be it known that I, ALBERT L.-CLAPP, a citizen of the United States, residing at Danvers, in the county of Essex and State of Massachusetts, have invented new and useful Improvements in Fiber Board, of which the following is a specification.

Theobject of the present inventionis to produce a dense, relatively hard, sheet material, which, when subjected toheat and high pressure, may be molded into buttons, phonograph records, printing plates, insulators and thelike.

I have discovered that waste animal matter, such as fleshings from tanneries, waste bones, fish scraps, waste hair from tanneries, either washed and cleaned or containing lime and solid animal matter, when beaten out in the presence of cellulose and water to the point of hydration of the cellulose and then formed into sheets and dried, can be used for many purposes including those stated. On subjecting such sheets to the action of heat and pressure, the animal matter is converted into a cementitious material which binds the fibers together, with the result thatdthe sheets are hard, compact, dense and r1g1 The initially formed sheet may be cut into blanks ofappropriat'e size and shape, and the blanks molded under heat and pressure to produce buttons, phonograph records, printin plates or the like. The pressure should be relatively high,say 1500 to 2000 pounds per square inch, and the temperature may range from about 200 F. to 350 F. to secure excellent results. When the initially formed and dried sheet is flat pressed under heat, it remains permanently flat, yielding 40 readily to the designs or impressions formed in the mold, and, if molded in other forms, I the material permanently sets.

In carrying out my process, it is sometimes necessary to condition the animal matter so that it may be readily beaten out with the cellulose. For example, it must be reduced in some cases to small pieces, as when it takes the form of fieshings, bones or fish scraps, and soaked in hot water for several hours, say from 8 to 10 hours; but such animal matter as hair, fine scraps of skin or flesh, bone meal and the like may be beaten out with the cellulose stock without previous treatment -since such matter is usually of suflicient fine- Application filed July '19, 1921. Serial No. 485,977.

ness as readily to disintegrate during the beating operation. 7

In carrying out my process, it is essential that the cellulosic materials should be beaten until thecellulose. fibers are fairly well hydrated so as to feel slimy to the touch and to be coated with a cellulose muscilage, or so that the stock will be in the condition known as slow as distinguished from free stock.

As illustrating how the process may be practiced in the production of a sheet material suitable for the manufacture of counter stifi'eners, I furnish a beater engine, such as used in the paper art, with say 20% to 30% by weight of waste hair (cow or goat hair) from tanneries (or wool if desired), and to 70% of cellulosic material such as sulphate or sulphite pulp, or the screenings thereof, together with sufficient water to circulate the stock. This mixture then is beaten hard and carefully and for sufficient time to well hydrate the cellulose to produce a slow or slimy stock. In this case, I prefer to use a heater roll in which the knives are not so sharp as to cut the hair to too great an extent, as I find that the best results are secured in disintegrating the hair by a brushing or bruising action which causes the individual hairs to swell and soften. Ordinarily the beating may require from 10 to 12 hours, although the'time of treatment is of no importance, since the condition of stock is the criterion in determining whether the beating operation has been sufiiciently performed. The stock is now formed into a sheet of the desired thickness by the use of a suitable paper-making machine, for example, a wet or cylinder machine so-called. After the sheet has been removed from the roll and dried, it is close, relatively hard, dense and compact. The hair serves as a cementitious agent, under the conditions stated in binding the cellulose fibers together. Blanks cut from the sheet, skived and molded by the ordinary operations into the form of counter stiifeners, are hard, dense, more or less polished, and the skived edges show practically no laminations.

In the process I may substitute other animal matter, such, for example, as bone meal, scraps of hides or skins resulting from fieshing them, fish scraps, etc. The proportions of the ingredients may vary to 1 considerable extent. Thus I may, in some cases, use 50% or more by weight of animal matter and the balance of cellulosic material such as waste kraft paper. When the sheet materials are subjected to heat and pressure such as hereinbefore referred to, they form a very hard, horny and densemass in whlch the binding action of the animal matter 1s greatly increased. The material thus lends itself particularly, where a relatively large proportion of animal matter is employed, to the manufacture of buttons, talking machine records, printing plates and the like.

It is sometimes desirable to treat the ammal stock chemically during the beating operation, as I find that this produces thereby a more glutinous or better cementitious binding agent which yields readily to heat and pressure, and it obviates the necessity of prolonged beating since, under such conditions, the cellulose hydrates with relative rapidity. This chemical treatment consists in the addition of a solvent of animal mat ter, such. for example, as caustic soda, any of the alkali earth metals, sulphides, e. g. sodium sulphide, or their equivalents, and the subsequent precipitation of the solids by a suitable agent such as alum. For example. I furnish a beater engine with 50 parts fleshings or hair, and 50 parts of cellulose in the form of mixed paper, together with sufficient water for the circulation of the stock, and then add 5 parts caustic soda. This mixture-is beaten for about 6 or 7 hours, or until the cellulose stock is properly hydrated. whereupon 15 parts of aluminium sulphate are added. The alum acts upon the dissolved portion of the animal matter, and produces a gelatinous precipitate which uniformly commingles with the hydrated cellulose and undissolved animal matter. The pulp is formed into sheets and dried as previously described. The sheets, thus produced, may be subjected to pressure or to both heat and pressure. In carrying out the beating operation, in the manner herein described, all of the animal matter is not dissolved by the alkali, but is only partly dissolved. that portion which is dissolved being precipitated by the alum in an in soluble form. Thus. in this case, both the free hair or animal matter and the gelatinous aluminum precipitate act together, under the heat and pressure to which the drv sheet is subjected to bind or cement the fibers together and thereby produce a hard, hornv. dense product.

Where dry hair is used as it comes from the tanneries. I find that I can secure the caustic reaction by using a weaker alkali such as sodium carbonate. In this case, the soda reacts with the lime carried by the hair, forming caustic soda which produces the solvent action on the hair. Hair from the tanneries may contain about 5% to lime, and, by using about 3% to 8% sodium carbonate per weight of dry hair, and 1ntroducing this into the beater engine with the cellulose and beating properly, excellent results are obtained.

It will, of course, be understood that I do not limit myself to specific proportions in carrying out my process. For phonograph records and printing plates, I find that 50% to 60% animal matter to 50% to 40% cellulose gives the best results, as the larger the proportion of animal matter, the denser and more rigid are the products. F or button board, on the other hand, good results are secured when only 10% to 30% of animal matter is used.

As thus far described, the process may be carried on and the products produced without cooking or digesting the raw materials. But I have also discovered that all of the animal matter may be dissolved, and excellent sheet material produced, by digesting the animal matter and cellulose with caustic soda under heat and pressure prior to the beating operation. Thus the animal matter and cellulose, together with about 5% of caustic soda, are cooked in a closed digester with water, at pounds pressure for about 3 to 5 hours. The cooked pulp is then introduced into a heater engine and beaten out as hereinbefore described. This method of practicing the process has the advantages that all of the animal matter is dissolved and a greater percentage of gelatinous aluminum precipitate is produced, and that a smaller proportion of animal matter can be used, since to animal matter in this case will give the results equivalent to those obtained, without cooking, by to thereof. However, in many cases it is preferable to dispense with the cooking,-as the direct beating of the stock without the preliminary step of cooking is more economical in time and eX- pense.animal matter being sufliciently cheap to render the quantity used of relative unimportance.

For certain purposes, sheet material, produced as herein described by hvdrating cellulose material in the presence of animal mat ter, may be calendered and finished for the manufacture of innersoles, counter stiffeners, heels, shank stili'eners. trunks. boxes, etc. For such purposes, I may employ about 30% of animal matter. 2% to 8% caustic soda, and cellulose stock (e. kraft paper or sulphate pulp) 62% to 68%, and subject the mass to sufliciently hard heating to hydrate the cellulose. To make the finished product more water-repellent. about 5% to 10% rosin size is added to the stock in the beater. The dissolved animal matter and the rosin size are precipitated by alum.

As indicating characteristic furnishes, the following examples are given.

beaten for -to 12 hours;

For button board,. printing plates, etc,-

' GOparts sulphate pulp orkraft paper, 10

parts fleshings, 30 parts hair, 2.part s caustic soda, 5 parts rosin, and 18 parts alum. After the cellulose stock, the hair, fle'shings and caustic soda are beaten out for"5 to 6 hours,

the rosin is added and the stock beaten for about 18 to 20 minutes, after which the alum is added. I

For printing plates, phonograph records, etc., parts kraft paper, 50 parts bone meal, 10 parts rosin size and 15 parts alum.

The kraft paper and the bone meal are beaten out hard for about 10 to 12 hours until the cellulose is well hydrated, the size added and beating continued for 18 to 20 minutes, after which alum is added. The stock is run into sheets of, about .88 inch thickness and dried. The end products are produced by subjecting blanks cut from the sheet to heat and high pressure in molds of the re uisite size and shape.

\Vhi e articles molded under heat andpressure from dried sheets formed as herein-- described possess a good appearance, are hard, firm, dense and rigid. yet they lack a fine finish and luster, but I remedy this by coating the initially formed and dried sheet material with 'a suitable substance which yields under heat and pressure and imparts a luster or finish. For example, I may use a solution of such gums as sandarac, shellac, or other suitable resins or resinous substances, phenol resins or their e uivalent. Thus, for making buttons, the dried board may be coated wlth an alcoholic solution of shellac or phenol resin, to which coloring matter may be added if desired; When the solvent has evaporated, the sheet or board is cut into blanks, which are molded under heat and pressure in appropriate molds. The heated mold causes the coating to flow uniformly and impart a fine luster to the finished buttons. When shellac is used, .it is necessary to cool the mold before removing the buttons, but, when a phenol-resin varnish is empl0yed,tl1e buttons can be removed while hot, as the phenol resin is converted into a compound unaffected by heat. It is desirable in some cases, instead of coating the whole sheet, to coat the blanks cut therefrom, by dipping them into the coating solution and permitting them to dry before molding them.

In referring 'to the application of heat and pressure, I mean to distinguish from the usual hot calendering operation in which a sheet is passed between hot calendering rolls, for, in my case, the material is confined during the pressure. That is, the pressure is accoomplished by molds or fiat latens, in which there is a directpressure or av predetermined time against the entire area of both faces. The period of pressure may vary,depending upon the thickness of the board, from two toninety seconds. The

molds or platens are heated in any suitable way to a temperature ranging from about 200. to 350 F. de' ending upon the'charac ter or thickness 0 the material.

What Iclaim is:

.. 1. That step in the process of producing a dry moldable material, which com rises beating out cellulose in the presence 0 animal matterand water until .the cellulose ishydrated to a point of sliminess.

2. The process of producing moldable material. which comprises beating out cellulose in the presence-of animal matter and water until the cellulose. is hydrated to sliminess, and then forming the pulpy'mass into a sheet and drying the sheet.

3.. The process of producing moldable materi'al, which comprises beating out cellulose in the presence of animal matter and water until the cellulose is hydrated to sliminess, then forming the pulpy mass into a. sheet and drying the sheet, and finallymolding the sheet or portions thereof under heat an pressureinto the desired form.

4. The process of reducing a material, that. is moldable and when dry, which comprises the step of beating out waste hair and cellulose in water until the cellulose is hydrated to sliminess.

er heat and pressure a 5. Theprocess of producing moldable material, which comprises the step of beating out waste hair, cellulose and a solvent for the hair, until the cellulose ishydrated'to sliminess.

6. The herein described process which comprises the step of beating out cellulose in the presence of animal matter, an alkali and water, until the cellulose reaches a point of sliminess, and then adding a precipitating agent to precipitate the dissolved animal matter in the form of a gelatinous mass.

7. The herein described process for producing a hard horny mass when molded under heat and pressure, which comprises the step of beating out cellulose in the presence of animal matter, an alkali and water, until the cellulose reaches a point of sliminess, then adding a precipitating agent to precipitate the dissolved animal matter, sheeting and drying the pulpy mass thus produced, and molding the same under heat and pressure.

8. The herein described process which comprises beating out cellulose, limed .hair,

an alkali and water, adding a preci itating 9. The herein described process which comprises beating out cellulose in the presence of animal hair and water until the cellulose is hydrated to a point of sliminess, sheeting and drying the pulpy mass thus produced, and molding portions of the sheet under heat and pressure to the desired form, the final product having the characteristics of density, horniness and Water repellence. 10. The herein described process which comprises beating out cellulose, animal matter, a solvent for the animal matter and water until the cellulose is hydrated to a point of slirniness, adding a precipitating agent for the dissolved animal matter, sheeting and drying the pulpy mass thus obtained, and then subjecting the sheet or portions thereof to heat and high pressure.

11. The herein described process which comprises beating out cellulose in the presence of animal matter and water, sheeting and drying the pulpy mass thus produced, coating the sheet or portions thereof with a finishing material capable of yielding to heat and pressure, and finally subjecting such sheet or such portions thereof to heat and pressure to mold them to the desired form.

- 12. A process of producing a dense horny inflexible molded material, which-comprises beating out cellulose in the presence of animal matter and Water, then forming the pulpy mass into a sheet and drying the sheet, and finally molding the dry sheet or portions thereof under heat and high pressure into the stated form.

13. A process as herein described, which comprises beating out the cellulose in the presence of animal matter, an alkali and water, adding a precipitating agent to precipitate the dissolved animal matter on the beaten-out fibers, drying the pulpy mass, and then subjecting the same or portions thereof to heat and high pressure.

14. A hornlike product consisting of previously hydrated cellulose fiber and animal matter in physically homogeneous admixture in which the animal matter serves as a cementitious binder to bind together the previously hydrated cellulose fibers.

15. A hard dense horny product such as herein described, comprising previously hydrated cellulose and dissolved and precipitated animal matter in a homogeneous admixture, the animal matter serving as a cementitious binder for the previously mucilaginous-coated cellulose fibers.

In testimony whereof I have affixed my signature.

ALBERT L. CLAPP. 

